Containers of bulk material are normally dumped mechanically wherever the weight of the loaded container exceeds that which can be handled easily by one man. The dump truck discharging its load of gravel is a familiar sight, and specialized machinery has been developed to empty an entire railroad car full of coal into a large hopper by gripping the car securely, and proceeding to rotate it about a horizontal axis parallel to the length of the car. These same principles are applicable through the full range of size of containers, except that it has been difficult to handle relatively small containers in this manner without producing a cost problem. Practically any factory has an endless number of applications involving bulk containers handling from a hundred to a thousand pounds of material, which is far in excess of that which can be handled properly by workmen without special equipment. The number of these applications, however, and the size of the loads involved, are such that the cost outlays for special-purpose dumping equipment of the type currently available are excessive. The present invention is directed primarily at mechanizing dumping operations of this type, where the containers involved are handled conveniently by a standard lift truck.